Cerium(IV) Ammonium Nitrate Is an Excellent, General Catalyst for the Friedländer and Friedländer−Borsche Quinoline Syntheses: Very Efficient Access to the Antitumor Alkaloid Luotonin A

The use of cerium(IV) ammonium nitrate as a catalyst of the Friedländer reaction allows the synthesis of polysubstituted quinoline derivatives in excellent yields, avoiding the traditional harshly basic or acidic conditions. Unlike most other previously known reagents, CAN allows double condensations and is also an excellent catalyst for the Borsche variation of the Friedländer reaction, which has been applied to the very efficient synthesis of the antitumor alkaloid luotonin A.